Shorten Dipole for 10 & 40m. Bands (by SV1XY)

FIG.1 below shows a shorten Dual-Band Dipole with overall length of about 11 m. For this antenna I do not use traps but simple inductors, in order to cover the 10 & 40 m. Bands.

A = 2,7 m B = 2.8 m

L= 41 turns (close), 1mm wire on a plastic rod 2,5 cm diameter.

FIG.1

Using inductors, the total length of antenna is about 50% of a full size 40m. Band Dipole.
The internal part of antenna (2 "A" sections) is a full dipole for 10m Band. Then,
the inductors acting as "traps" for the rest length of antenna. On 40m. Band, the antenna works as coil-loaded
with some losses in efficiency, but on the other hand, it's a very small-size dipole for this band. That is a good idea for a 40m-Band rotary dipole ( plus 10m ! ).

For best SWR on 10m, you must increase or decrease the "A" sections. Then, looking for best SWR on 40m. by adjusting the "B" sections.